Method of making keys.



s. 0. MERRIGK.

METHOD OF MAKING KEYS.

APPLICATION FILED JUNE 24,1914. 1,1 12,020. a ented Sept. 29, 1914.

m "III UNITED STATES PATENT OFFICE.

SILAS C. MERRICK, OF NEW BRIGHTON, PENNSYLVANIA, ASSIGNOR TO THE STANDARD HORSE NAIL COMPANY, OF NEW BRIGHTON, PENNSYLVANIA, A CORPORATION 01 PENNSYLVANIA.

METHOD OF MAKING KEYS.

Specification of Letters Patent.

Patented Sept. 29, 1914.

To all whom it may concern: 5

Be it known that I, SILAs C. MERRIOK, a citizen of the United States, and resident of New Brighton, Beaver county, State of Pennsylvania, have invented certain new and useful Improvements in Methods of Making Keys, of which the following is a specification.

This invention relates to the manufacture of what is known to the machinery trade as the Woodrufi' key.

This key is in the form of a semi-cylindrical prism and it is the object of the present invention to provide an improved and expeditious method of manufacture of these keys whereby the cost of manufacture is reduced to a minimum and the character of the product improved.

My invention is illustrated in the accompanying drawing in which,

Figure 1 is a side view of a cutter for the keys;-Fig. 2 is a section on the line 2-2 of Fig. 1, and, Fig. 3 is a perspective view of one of the keys.

According to my improved method of making these keys I arrange a series of bars 10 of suitable material in parallel relation, as shown in Fig. 2, the bars being of rectangular cross section and of a width in the direction of feed of the cutter equal to the thickness of the keys. The bars are suitably clamped to the table of a milling machine and a series of milling cutters 11 arranged on the usual shaft 12 are so shaped as to be capable of forming the curved side of the keys and severing them from the bars at one operation.

The table with the bars thereon is fed, relatively to the cutters, in the direction of the lower arrow in Fig. 2, the cutter, preferably rotating in the direction indicated by the upper arrow. It will be noted that the action of the cutter at the point 13 is such that it tends to lift the bars to some extent. This is immaterial so long as the keys are attached to the bars by a considerable area of metal, but would dislodge the ke s when they were almost severed from t 0 bars. From Fig. 2, however, it will be observed that when the keys are nearly severed from the bar, as indicated at 14, the direction of the force applied thereto by the cutter is substantially horizontal and there is little or no lifting tendency so that the cutter will completely sever the keys from the bars without dislodging any of them. The bars, being arranged side by side, reinforce each other so that the cutter passes through practically a solid piece of metal and no fins or burs are formed alon the edges of the keys and a practically per ect product is therefore produced. By havin bars 10 of different thicknesses keys of di erent thicknesses may be cut at one operation and thus facilitate the production of keys of assorted SIZES. I

Having thus described my invention what I claim as new and desire to secure by Letters Patent is.

1. The herein described method of making semi-cylindrical prismatic keys which consists in milling transversely through a bar of rectangular cross section, the width of the bar in the direction of feed of the cutter being the thickness of the key and the cutter forming the curved side of the key and severing the key from the bar in one operation.

2. The herein described method of making semi-cylindrical prismatic keys which consists in milling transversely through a series of bars of rectangular cross section arranged side by side in the direction of feed of the cutter, the cutter forming the curved sides of the keys and severing the keys in one operation. V

In testimony whereof I aflix my signature in presence of two witnesses.

SILAS o. MERRICK.

Witnesses:

E. H. SEIPLE, FRED. S. MERRIOK. 

